If you want to use the patched version,and you do, believe me, don't download the megapatch. The best thing is to collect the best cars and use GP4 master or wadupdater to change your cars.wad. I am playing both F1C and Gp4 at the moment, I love the both but prepare yourself, GP4 is not as easy to edit. You need to learn the editors. Do a search here for the other stuff you will want like GPxpatch (this is ssential) and Gp4tweaker. There has been a huge amount of work done in this community, take advantage of it!
Good luck and reserve a lot of time ..say goodbye to your loved ones, you are about to become immersed in an orgy of editing and hopefully driving.
Larry
AMD 3000+,Epox EP-8RDA,Ram 1536mb 333 DDr, Rad 9800 pro omega 2.4.96, dx9b, Audigy, MOMO FF,winxp